Slurry hydroconversion catalysts

Abstract

Systems and methods are provided for slurry hydroconversion of a heavy oil feedstock, such as an atmospheric or vacuum resid, in the presence of an enhanced or promoted slurry hydroconversion catalyst system. The slurry hydroconversion catalyst system can be formed from a) a Group VIII non-noble metal catalyst precursor/concentrate (such as an iron-based catalyst precursor/concentrate) and b) a Group VI metal catalyst precursor/concentrate (such as a molybdenum-based catalyst precursor/concentrate) and/or a Group VI metal sulfided catalyst.

What is claimed is: 
     
       1. A method for forming a slurry catalyst, comprising:
 dispersing a first catalyst precursor comprising iron and a second catalyst precursor comprising molybdenum in a hydrocarbonaceous material comprising a heavy oil fraction, an amount of molybdenum in the second catalyst precursor in the hydrocarbonaceous material being about 250 wppm or less, based on inclusion of the catalyst/system into a heavy oil feedstock to be hydroconverted, a weight ratio of the iron in the first catalyst precursor to the molybdenum in the second catalyst precursor in the hydrocarbonaceous material being at least 10; wherein dispersing the first catalyst precursor in the hydrocarbonaceous material comprises dispersing an aqueous solution of the first catalyst precursor in the hydrocarbonaceous material, or wherein dispersing the second catalyst precursor in the hydrocarbonaceous material comprises dispersing an aqueous solution of the second catalyst precursor in the hydrocarbonaceous material, or a combination thereof, thereby forming a first and/or a second catalyst precursor concentrate; and 
 sulfiding the first catalyst precursor and the second catalyst precursor to form a sulfided catalyst system. 
 
     
     
       2. The method of  claim 1 , wherein the second catalyst precursor comprises phosphomolybdic acid and/or a different molybdenum heteropolyacid. 
     
     
       3. The method of  claim 1 , wherein the iron catalyst precursor comprises a water-soluble precursor; or wherein the iron catalyst precursor comprises a counter-ion or ligand comprising sulfate, nitrate, acetate, citrate, carbonyl (carbon monoxide as a ligand); or a combination thereof. 
     
     
       4. The method of  claim 1 , further comprising heating the hydrocarbonaceous material, after dispersing the first catalyst precursor but prior to sulfiding the first catalyst precursor, to a temperature of about 150° C. or less to remove at least a portion of water present in the hydrocarbonaceous material. 
     
     
       5. The method of  claim 1 , wherein an amount of the iron in the sulfided catalyst system is about 500 wppm to about 30,000 wppm, based on inclusion of the catalyst/system into a heavy oil feedstock to be hydroconverted. 
     
     
       6. The method of  claim 1 , wherein at least one of a) the amount of the molybdenum in the second catalyst precursor in the feedstock is about 150 wppm or less; b) an amount of the molybdenum in the sulfided catalyst system is about 150 wppm or less; c) a weight ratio of the iron to the molybdenum in the sulfided catalyst system is about 30 or less; or d) a combination thereof. 
     
     
       7. The method of  claim 1 , further comprising contacting the sulfided catalyst system with hydrogen gas and a sulfur source comprising hydrogen sulfide and/or elemental sulfur to form an activated catalyst system. 
     
     
       8. The method of  claim 1 , further comprising hydroprocessing a feedstock under effective slurry hydroconversion conditions to form at least a converted fraction and a pitch fraction, at least a portion of the pitch fraction optionally being recycled for exposure to the effective slurry hydroconversion conditions. 
     
     
       9. The method of  claim 8 , wherein the effective slurry hydroconversion conditions comprise a temperature of about 400° C. to about 480° C.; a hydrogen partial pressure of about 250 psig (1.7 MPag) to about 3400 psig (23.4 MPag); and a space velocity of about 0.05 v/v/hr −1  to about 5 v/v/hr −1 . 
     
     
       10. The method of  claim 8 , wherein the sulfided catalyst is separated from at least one of the converted fraction and the pitch fraction using a cross-flow filter. 
     
     
       11. The method of  claim 8 , wherein at least a portion of the pitch fraction is exposed to oxidative ring opening conditions to form an oxidized pitch fraction. 
     
     
       12. A method for forming a slurry catalyst, comprising:
 dispersing a first non-sulfur-containing catalyst precursor comprising iron in a hydrocarbonaceous material comprising a heavy oil fraction, the hydrocarbonaceous material further comprising a sulfided molybdenum catalyst, an amount of molybdenum in the sulfided molybdenum catalyst in the hydrocarbonaceous material being about 250 wppm or less, based on inclusion of the catalyst/system into a heavy oil feedstock to be hydroconverted; and 
 sulfiding the first catalyst precursor to form a sulfided catalyst system, and 
 contacting the sulfided catalyst system with hydrogen gas and a sulfur source comprising hydrogen sulfide and/or elemental sulfur to form an activated catalyst system, 
 wherein a weight ratio of the iron to the molybdenum in the sulfided catalyst system is at least about 10. 
 
     
     
       13. The method of  claim 12 , wherein an amount of the iron in the sulfided catalyst system is about 500 wppm to about 30,000 wppm. 
     
     
       14. The method of  claim 12 , wherein a weight ratio of the iron to the molybdenum in the sulfided catalyst system is about 30 or less. 
     
     
       15. The method of  claim 12 , further comprising hydroprocessing a feedstock under effective slurry hydroconversion conditions to form at least a converted fraction and a pitch fraction. 
     
     
       16. An activated catalyst system formed by a method comprising:
 dispersing a first catalyst precursor comprising iron and a second catalyst precursor comprising molybdenum in a hydrocarbonaceous material comprising a heavy oil fraction, an amount of the molybdenum in the second catalyst precursor in the hydrocarbonaceous material being about 75 wppm to about 250 wppm, based on inclusion of the catalyst/system into a heavy oil feedstock to be hydroconverted, a weight ratio of the iron in the first catalyst precursor to the molybdenum in the second catalyst precursor in the hydrocarbonaceous material being about 10 to about 30; 
 sulfiding the first catalyst precursor and the second catalyst precursor to form the sulfided catalyst system; and 
 contacting the sulfided catalyst system with a sulfur source and hydrogen gas under conditions sufficient to form an activated catalyst system. 
 
     
     
       17. An activated catalyst system formed by a method comprising:
 dispersing a first non-sulfur-containing catalyst precursor comprising iron in a hydrocarbonaceous material comprising a heavy oil fraction, the hydrocarbonaceous material further comprising a sulfided molybdenum catalyst, an amount of the molybdenum in the sulfided molybdenum catalyst in the feedstock being about 75 wppm to about 250 wppm, based on inclusion of the catalyst/system into a heavy oil feedstock to be hydroconverted; 
 sulfiding the first catalyst precursor to form a sulfided catalyst system; and 
 contacting the sulfided catalyst system with a sulfur source and hydrogen gas under conditions sufficient to form an activated catalyst system, 
 wherein a weight ratio of the iron to the molybdenum in the sulfided catalyst system is from about 10 to about 30.